Inertia and point detonation impact fuze



June 5, 1956 F. B. HALE INERTIA AND POINT DETONATION IMPACT FUZE Filed 001;. 28, 1952 gwue/wbo'n Frank B. Hale W Fa.

INERTIA AND POINTUDZITONATION IMPACT Frank B. Hale, Bel Air, Md., assignor to the United States of America as represented by the Secretary of the Army Application October 28, 1952, Serial No. 317,373

1 Claim. (Cl. 10273) (Granted under Title 35, U. S. Code (1952), see. 266) The invention described herein may be manufactured and used by or for the United States Government for g vernmental purposes without the payment to me of any royalty thereon.

This invention relates generally to bomb fuzes and specifically to a bomb fuze having an improved firing arrangemen't.

It is an object of this invention to provide an improved fuze of the impact type which is capable of both point detonation and inertia detonation. 7

It is another object of this invention to provide a bomb fuze which is particularly adapted to be incorporated in a blunt nose bomb of the type which are normally stored, dispersed and dropped in clusters, and which upon separation from the cluster after being dropped travel independently to the target. I

It is still another object of the invention to provide a bomb fuze which may be incorporated in either a rotating or non-rotating bomb, which will function over a wide range of impact angles and which will function without respect to the nature of the, target material.

It is a further object of this invention to provide a bomb fuze of the impact type wherein structure is provided for assuring the functioning of the fuze upon impact either as the result of inertia, which results when the bomb strikes a hard material such as a concrete target, or by point detonation, which results when the bomb strikes a soft material such as soft earth.

It is the specific object of the. invention to provide an improved bomb fuze of the impact type wherein the primer is resiliently mounted so that it will be forced against the firing pin by the force of inertia when the bomb strikes a hard target, and wherein the firing pin is secured to a rupturable disc so that it will be separated from said disc and be forced against the primer when the bomb strikes a soft target.

The above and other objects of the invention will become apparent from the following specification and claim taken in connection with the accompanying drawings wherein:

Fig. 1 is a sectional view taken through the center of my improved bomb fuze.

Fig. 2 is an elevational view, with portions broken away and shown in section, of a bomb which incorporates my improved fuze striking a hard target.

Fig. 3 is a sectional view similar to Fig. 1 showing the relative position of the parts momentarily after the bomb shown in Fig. 2 strikes a hard target.

Fig. 4 is a view similar to Fig. 2 showing a bomb which incorporates my improved fuze striking a soft target.

Fig. 5 is a view similar to Fig. 1 showing the relative position of the parts of the fuze momentarily after the bomb shown in Fig. 4 strikes a soft target.

Referring to Fig. 1, my improved fuze is generally indicated by reference numeral 10. Fuze comprises a cylindrical body 12 which is threaded at one end so that it may be secured in the fuze socket of a bomb. Fuze nited States Patent body 12 has a neck portion 16 of reduced diameter on its end opposite tothreaded end 14. Fuze body 12 has an irregularly shaped passageway formed therein by a series of bores which extend from the end of the fuze body 12 that is threaded at 14, which will be designated as the nose end of the fuse, through said body to and through said neck portion 16. The passageway comprises the following bores, all of which communicate with each other to provide a continuous, central passageway of varying diameter through the fuze body: central threaded bore 18, converging, conically-shaped bore 29, narrow cylindrical bore 22, reduced cylindrical bore 24, further reduced cylindrical bore 26, still further reduced cylindrical bore 28 and threaded, enlarged, cylindrical bore 30. Threaded portion 32 of the burster tube 34 is secured in the threaded bore 30, which is positioned in the neck portion 16. A burster charge 36 is positioned in the burster tube 34. A flanged cup 38 is positioned in the bore 28 contiguous with the burster charge 36 and houses a burster, primer charge 49. Detonator 42, which is appropriately housed in the casing 44, is positioned in the bore 26 and contacts the cup 33. Bore 24 houses primer carrier 46 which comprises a weighted, cylindrical, body portion 48 which has a flange 50 formed at one end. Flange St) has a sliding fit in bore 24. Primer carrier 46 has a bore 52 formed therein which communicates with enlarged counterbores 54 and 56 at its ends. Enlarged counterbore 54yhouses a relay charge 58, enlarged counterbore 56 houses primer 6% and the bore 52 houses delay powder 62 therebetween. Annular, spring retainer plate 64 is positioned in narrow bore 22 and maintained rigidly in position therein by the leading edge of the conical portion 66 of the plug 68. Compression spring 70 surrounds the cylindrical body portion 48 of the primer carrier 46, and abuts flange 50 of said primer carrier and the annular plate 64, and normally urges said primer carrier to the position shown in Fig. 1 wherein it contacts detonator casing 4 5. Plug 63 is externally threaded at 72 for the purpose of permitting said plug to be secured in the threaded bore 18. Plug 68 has a series of bores and counterbores formed therein which communicate with each other to provide an irregularly shaped passageway which extends completely through the central portion thereof. Said passageway comprises cylindrical, threaded bore 74-, reduced, narrow bore 76, further reduced, cylindrical bore 78 and still further reduced, cylindrical bore 30. A firing pin is designated generally by reference numeral 82 and comprises the following structure: cylindrical body portion 84, which has a sliding fit in the bore 80, striker pin 86 and flange 83 which has a sliding fit in bore 78. A thin metal disc 90 is secured to the flange 88 of firing pin 82 by any conventional securing means, such as screw 92. The thin, metal disc 9%, which is larger in diameter than the flange 83, is po sitioned in the narrow bore 76 and has its rim secured therein by the leading edge of externally threaded sleeve 94 which is secured in the threaded, cylindrical bore 74 of plug 68. The interior of sleeve 94 and the exposed portions of the thin, metal disc 9% constitute a cavity which is open to the atmosphere at the nose end of the fuze.

Fig. 1 shows the relative position of the various parts of the fuze at the time the fuze is inserted into the fuze socket of a bomb. It should be noted that at this time all of the parts shown in Fig. 1 except the primer carrier 46 and the firing pin 82 are rigidly maintained in position, and that the primer carrier 46 is slidable in the bore 24 but normally urged to the position shown in Fig. 1 by the spring 70. Further, it should be understood that whereas the firing pin 82 is normally held in the position shown in Fig. 1, under certain conditions to be subsequently described, it is capable of being detached from 3 the disc 90 and to slide in the bores 78 and 80 toward the primer 60 in the primer carrier 46.

Fig. 2 shows a bomb 96, which carries fuze 10 in its fuze socket 98, striking a hard target 100. Fig. 3 shows the position of the parts of the bomb fuze 10 an instant after the bomb 96 strikes the hard target. From Fig. 3 it will be seen that the primer carrier 46 has been moved to its forwardmost position (nearest the nose end of the fuze) by the force of inertia, and that it has compressed the spring 70 and forced the primer 60 onto the striker pin 36. It will be noted that all other parts of the fnze occupy the same position relative to each other that they did in Fig. 1. When the primer contacts the striker pin 86, the primer 60 functions to set off the chain of events which ultimately lead to the ignition of the burster charge 36 and the bomb filling itself. This chain of events includes the activation of the primer 60, the delay powder 62, the relay 53, the detonator 42, the burster primer 40 and the burster charge 36.

Fig. 4 shows a bomb 102 which carries fuze 10 in its fuze socket 104 striking a soft target such as soft earth 106. Upon impact, a portion 108 of the earth enters cavity 110 formed in the nose end of fuze 10. Fig. 5 shows the relative positions of the parts of the bomb fuze after bomb 102 strikes soft earth. It should be understood that when the bomb 102 strikes a soft target such as earth 106 there is not a sufiicient amount of inertia to force the primer carrier 46 forwardly against the striker pin 36 as is the case when it strikes a hard target. Therefore, primer carrier 46 occupies the same position relative to the bomb fuze casing 12 as it did in Fig. 1. It will be seen in Fig. 5 that the portion 10% of earth that enters the cavity 110 exerts a force in the direction of the arrow 112 which is sufficient to rupture the thin, metal disc 90 and force the firing pin $2 rearwardly in the fuze body 12 with great force until the striker pin 86 contacts the primer 60 thereby actuating it and setting off the chain of events that ultimately actuate the bomb filling.

From the foregoing disclosure, it will be apparent that I have provided a bomb fnze which is capable of functioning either as an inertia-detonated fuze or a point cletonating fuze depending upon the character of the target it strikes. It will further be apparent that my fuze is adapted to be incorporated in either a rotating or nonrotating bomb, that it will function over a wide range of impact angles and that it will function regardless of the nature of the target material. Still further, it will be observed that my improved bomb fuse may be readily incorporated in the fuze socket of the widely used blunt nose, cluster bombs.

Having described my invention in great detail, it is not desired thereby to limit the invention to the precise structure shown, but it is intended to embrace all changes that might be made by those skilled in the art which fall within the spirit of the invention or the scope of the appended claim.

I claim:

A fuze comprising a fuze body having a nose end and an inner end, a non-uniform bore forming an axial passageway through said fuze body from said nose end to said inner end, an annular shoulder in said passageway facing said nose end; a thin metal disk positioned against said shoulder, a threaded sleeve holding said disk in po sition against said shoulder, a firing pin secured to said disk and coaxial with said passageway, said disk and firing pin closing said passageway and being spaced from the nose end a distance so that said disk and firing pin form with the walls of said threaded sleeve a cavity open to the exterior; a primer carrier slidably mounted in said passageway, a detonator in said passageway adjacent the inner end of said carrier, a bore in said primer carrier coaxial with said passageway, a primer mounted in said carrier bore adjacent the nose end thereof, a delay mounted in said carrier bore inwardly of said primer, and a relay charge in said carrier bore adjacent the inner end of said carrier, spring means normally holding said carrier away from said firing pin; said passageway, firing pin and primer carrier being so constructed that on impact with a substantially hard object said carrier has a range of movement against the action of the spring greater than the normal distance between said firing pin and said primer and on impact with a yieldable object said firing pin has a like range of movement upon rupture of said disk.

References Cited in the file of this patent UNITED STATES PATENTS 1,531,717 Remondy Mar. 31, 1925 1,705,206 Remondy Mar. 12, 1929 2,058,822 Petter Oct. 27, 1936 2,547,820 Hammar et a1. Apr. 3, 1951 2,601,827 Brandt July 1, 1952 FOREIGN PATENTS 352,215 Great Britain July 9, 1931 524,712 Great Britain Aug. 13, 1940 

